Dimas dorikly there is no prohibition to use power saving mode all the time. Maybe you just unable to access full experience of the phone, for example the 120hz refresh rate display and the light mode (dark mode opposite).
gineok2 For me, yes, I don’t see the point where the battery economy mode can be a problem, except if you want some application to work on continue.
ChrisJ I don’t know why for any phone be it 3a pro or my previous oppo or 4a pro the power saving mode feels like using more power than the normal one but for 4a pro i have not noticed it as much as on the other two.